Quantitation of Plasma Testosterone by Improved Competitive Protein-Binding Technique

1970 ◽  
Vol 16 (2) ◽  
pp. 111-117 ◽  
Author(s):  
J A Demetriou ◽  
F G Austin
Keyword(s):  
Protein Binding ◽  
Binding Assay ◽  
Plasma Testosterone ◽  
Normal Female ◽  
Adrenal Hyperplasia ◽  
Protein Binding Assay ◽  
Competitive Protein Binding Assay ◽  
Competitive Protein Binding ◽  
Male Subjects ◽  
Double Isotope

Abstract A method is described for quantitation of testosterone in plasma from females and males. The principal operations of extraction, chromatographic fractionation, and competitive protein-binding assay can be completed for eight duplicate samples in a single day. Experimental data used in the development of the test and the rationale for the specific operations and conditions are presented. The specificity of the method was established by comparing plasma testosterone concentrations determined by the double isotope derivative technique. Concentrations are reported for normal female and male subjects, and for patients with hirsutism, adrenal hyperplasia, Klinefelter’s syndrome, and other endocrine conditions.

RELIABILITY OF PLASMA TESTOSTERONE ASSAYS BY COMPETITIVE PROTEIN BINDING METHODS

1970 ◽  
Vol 65 (1_Suppl) ◽  
pp. S257-S274 ◽  
Author(s):  
C. A. Nugent ◽  
D. Mayes
Keyword(s):  
Protein Binding ◽  
Binding Assay ◽  
Binding Protein ◽  
Plasma Testosterone ◽  
Protein Binding Assay ◽  
Competitive Protein Binding Assay ◽  
Competitive Protein Binding ◽  
Double Isotope

ABSTRACT This report examines the reliability of different methods for competitive protein binding assay of plasma testosterone. Most of the methods give results similar to those reported by the most reliable of the competitive protein binding methods and by established double isotope derivative methods. In a few instances poor reliability was demonstrated. However, the reliability of the remaining methods usually had not been investigated thoroughly. An adequate examination of accuracy was one of the most frequent omissions in the investigation of the reliability of these methods. Differences between direct standards and samples containing known amounts of testosterone purified in the same manner as unknown samples can develop easily in competitive protein binding methods. These differences may be caused by substances other than the steroid being measured or by alteration of the labelled or unlabelled steroid. The interfering substance or altered steroid may be present before or appear during or after purification. The impurity may or may not be removed in purification and it may or may not bind with the binding protein. To detect these types of errors, accuracy studies should be done throughout the range of concentrations in which it is expected to apply the method.

Comparison of Results by Four Different Procedures for Determination of 17-Hydroxycorticosteroids

1973 ◽  
Vol 19 (7) ◽  
pp. 748-752 ◽  
Author(s):  
Joseph Bruton ◽  
Ting-Kai Li ◽  
Gerald D Smith
Keyword(s):  
Protein Binding ◽  
Binding Assay ◽  
Assay Procedure ◽  
Protein Binding Assay ◽  
Normal Individuals ◽  
Derivative Method ◽  
Competitive Protein Binding Assay ◽  
Competitive Protein Binding ◽  
Double Isotope

Abstract A Porter and Silber procedure, a fluorometric procedure, a double-isotope derivative procedure, and a competitive protein-binding assay procedure were used to determine 17-hydroxycorticosteroids in plasma from normal individuals and from patients with endocrinopathies. Results from each of these procedures were intercompared. Results of the fluorometric procedure and the competitive protein-binding assay compared favorably with results obtained by the more elaborate and difficult double-isotope derivative method. The Porter and Silber method is less specific. This study should be a useful aid in comparing values with those of other laboratories and in selecting the most advantageous method for use by a particular laboratory.

A Simplified competitive protein-binding assay for 25-hydroxycalciferol

1976 ◽  
Vol 68 (2) ◽  
pp. 99-105 ◽  
Author(s):  
B. Garcia-Pascual ◽  
A. Peytremann ◽  
B. Courvoisier ◽  
D.E.M. Lawson
Keyword(s):  
Protein Binding ◽  
Binding Assay ◽  
Protein Binding Assay ◽  
Competitive Protein Binding Assay ◽  
Competitive Protein Binding

A Competitive Protein-Binding Assay for 25-Hydroxycholecalciferol

1975 ◽  
Vol 17 (2) ◽  
pp. 57-57
Author(s):  
Yoshiki Seino ◽  
Tsunesuke Shimotsuji ◽  
Shintaro Okada ◽  
Teisuke Hiejima ◽  
Chiiko Ikehara ◽  
...  
Keyword(s):  
Protein Binding ◽  
Binding Assay ◽  
Protein Binding Assay ◽  
Competitive Protein Binding Assay ◽  
Competitive Protein Binding ◽  
25 Hydroxycholecalciferol
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